Each year throughout Australia, there are numerous electrical accidents at work involving electric shock, many of which are fatal.
An electric shock is defined as the effect when an electrical circuit and the current flows through a person's body; electrocution is death from electric shock.
There are many causes of electric shock and electrocution within the workplace, the most common of which is contact with overhead wires. This occurs when people misjudge the height or distance between the ground and overhead wires when carrying equipment such as poles and ladders.
Other frequent causes of electrical injuries include:
- not isolating the electrical supply
- working on 'live' electrical equipment
- inadequate maintenance
Even if you survive an electric shock, there can be serious side effects, including burns, eye damage, partial loss of limb function, neurological disorders such as confusion and memory loss, and injuries caused after the shock (eg falling off a ladder or contact with moving machinery).
Other side effects can include muscle spasms, respiratory arrest, cardiac arrest, and uncoordinated contractions of the heart.
As well as employers providing and maintaining, so far as is reasonably practicable, a working environment for workers and independent contractors that is safe and without risks to health, registered electrical contractors and licensed electricians must also comply with duties under the ES Act (or equivalent) and specific duties under the ES Regulations. The regulations incorporate the following Australian Standards:
- AS/NZS 3000 Wiring Rules
- AS/NZS 3012 Electrical installations – Construction and demolition sites (incorporated by reference in AS/NZ 3000).
Compliance with those Australian Standards is mandatory. Where conflict arises between a provision of this industry standard and a technical wiring provision of the referenced Australian Standard, the Australian Standard provision should be followed.
In order to avoid electrical injuries, a combination of the following is required:
- safe work practices
- maintaining electrical installations and appliances
Practical steps employers and employees can take to prevent electrical injuries:
- Maintain equipment and appliances through regular inspection. Look for any damage such as flickering, smoke, popping, hot fuses, etc. A safety checklist may be useful when carrying out inspections of electrical equipment.
- Disconnect broken appliances and have broken power points or frayed cords replaced immediately.
- Know the location of the main electricity supply in case of emergency.
- Keep electrical appliances away from water and wet areas. Never touch switches or power points with wet/damp hands.
- Don't overload circuits and fuses by using too many appliances from a single power point.
- Keep electrical cords off the floor to reduce the risk of damage from contact with sharp objects or drag.
- Have a system of work in place where the location of cables (overhead, underground) is determined before digging, drilling etc.
- Reduce the voltage - limit the supply voltage to the lowest needed to get the job done or where electrically powered tools are used, battery-operated are safest.
All construction switchboards installed for construction or demolition purposes must be designed and constructed to comply with AS/ NZS 3012. They must also:
- include a tie bar or other device to prevent strain on termination of cables and flexible cords. The tie bar or other means to prevent strain must be insulated and must not cause mechanical damage
- be securely attached to a pole, post or wall or other stable, free-standing structure designed to withstand external forces that may be exerted on the switchboard (eg from flexible cords)
- be protected from the environment by an enclosure meeting IP23 requirements
- be designed to ensure all main switches and isolating switches are accessible at all times, clearly marked and capable of being locked in an open (off) position
- have markings at least six millimetres high identifying all main/isolating switches
- incorporate insulated stands for supporting cables and flexible extension cords or have a stand fixed near the switchboard
- be fitted with a lockable door for isolation and security purposes that will not damage the cables when closed.
By ensuring the above measures are taken, it significantly reduces the risk of electric shock and electrocution. Following them can be a matter of life and death.